Where concepts meet the real world: A systematic review of ecosystem service indicators and their classification using CICES

We present a 'concept matching' systematic review linking the classes of the Common International Classification for Ecosystem Services (CICES, v4.3) to the ways scientists define and apply ES indicators in published studies. With the dual aim of creating an overview how the different services are measured in the studies, and determining if CICES provides an appropriate structure to accommodate the ES assessed in the practical literature, we reviewed 85 scientific papers from which 440 indicators were identified. Almost all CICES classes were represented, with cultural and some regulating (e.g. global climate regulation, pollination) ES being the most frequently considered. The four most frequently studied CICES classes (or class clusters) were global climate regulation, aesthetic beauty, recreation, and bio-remediation. Regulating and cultural services were more often assessed than provisioning services. Normalisation to unit area and time was common for indicators of several regulating and provisioning ES. Scores were most frequently used for cultural ES (except recreation) and some regulating services (e.g. flood protection). Altogether 20% of the ES indicators were quantified as an economic value, and monetisation is most frequently done for cultural and provisioning ES. Few regulating services, on the other hand, were monetised (including ones, like global climate regulation, for which appropriate techniques are relatively easily available). The work enabled a library of indicators to be compiled and made available. The findings can be used to help improve CICES so that it can provide a more robust and comprehensive framework for ecosystem assessments.